Last Updated on August 1, 2021 by Admin 1
Consider the partial output of the show ip bgp command:
Which of the following statements are TRUE about the given output? (Choose all that apply.)
- The 10.62.7.0 route is learned by the router through an iBGP neighbor.
- All five routes have been originated by an IGP.
- The router is aware of the best path for the 22.214.171.124 destination.
- There are four AS between the router and the 126.96.36.199 subnet.
The following statements are TRUE about the given output:
The 10.62.7.0 route is learned by the router through an iBGP neighbor.
All five routes have been originated by an IGP.The show ip bgp command displays information about the BGP routing table, including origin type, metric, next-hop addresses for every route learned by BGP, router ID, local preference, and BGP path. In the output, the character i in the first entry of the 10.62.7.0 destination indicates that the route was learned by an iBGP neighbor. The * symbol at the beginning of the routes indicate that they are valid routes, while the > symbol indicate that the route is the current best route.The i at the end of the entries under the Path column indicates that the routes have been originated by an interior gateway protocol (IGP). In the scenario output, all five routes have an i at the end of their respective entries. If the character e appears as the origin code, the routes are considered to have originated from an exterior gateway protocol (EGP). The origin code can also be the ? character, which implies that the origin of the route is unknown.The output also displays the next-hop addresses for the routes. The 188.8.131.52 subnet is a local route, and hence has its next-hop address as 0.0.0.0.The show ip bgp command also displays the local router’s ID (RID), local preference, weight, and next-hop addresses for every route learned by BGP. In this case, the RID of RouterA is 184.108.40.206 and the local preference, weight, and next-hop address for the 10.62.7.0 network are 100, 0, and 10.62.7.78, respectively. The metric and the next-hop address for the BGP routes can also be viewed by using the show ip route bgp command, as follows:RouterA# show ip route bgp
B 10.62.7.0 [200/0] via 10.62.7.78, 01:34:16
B 220.127.116.11 [200/0] via 10.62.7.78, 01:34:16
B 18.104.22.168 [20/100] via 10.62.7.115, 01:34:16The BGP table version can also be displayed by using the show ip bgp neighbors and the show ip bgp summary commands. The show ip bgp neighbors command also displays the address, ASN, and RID of neighbors of the local router, as shown below:RouterA# show ip bgp neighbors
BGP neighbor is 22.214.171.124, remote AS 200, external link
BGP version 17, remote router ID 126.96.36.199
BGP state = Established, table version = 16, up for 01:45:03
<output omitted>The show ip bgp summary command displays the RID and the BGP table version, as shown in the following output:RouterA# show ip bgp summary
BGP router identifier 188.8.131.52, local AS number 100
BGP table version is 17, main routing table version 18
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.62.7.90 17 200 56 55 18 0 0 01:42:13 27
10.62.7.145 17 300 34 33 18 0 0 00:31:20 0The router is not aware of the best path for the 184.108.40.206 route. The character h appears at the beginning of the entry for the 61.80.30 destination. This means that the route is in the history state currently and that the best route is not known.There are not four AS between the router and the 220.127.116.11 subnet. In the output, the Path column for the 192.1771.1.0 subnet lists four AS numbers. The four AS numbers refer to the ASNs traversed by the route from RouterA to the 18.104.22.168 subnet. The first AS refers to the first neighbor of RouterA; the second AS refers to the neighbor of the first neighbor; and so on. The last AS in the column is the AS of the 22.214.171.124. This implies that there are three AS (1, 2, and 3) that exist between RouterA and the subnet.
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